The basic form of sanitary napkin, upon which the present invention is an improvement, is well known. It is referred to variously as a curved, or three dimensional, or shaped product, usually with elasticized edges. In use, it is mounted on the crotch portion of an undergarment such as a panty and, for convenience in description, the working environment of the invention will be assumed to be in a panty as worn by a female. However, the inventive concept may also be applied to infant care and adult incontinent garments.
Essentials of the existing product are an absorbent element enclosed between a bodyside permeable cover and a garment side impermeable baffle. The cover and baffle extend laterally beyond the absorbent element, at least along its longitudinal sides, and are bonded together to form a “side edge.” Typically, at least longitudinally central portions of these side edges are gathered, or elasticized, tending to raise the side edges relative to the absorbent element so that the free form of the product is upwardly curved and somewhat cup shaped. Examples of this type of sanitary napkin are those sold by the Kimberly-Clark Corporation under the name Kotex® Natural Curved Maxi. Variations of the form and typical construction details are disclosed by Ellis et al. in U.S. Pat. Nos. 4,701,177 and 4,770,657, and Coe et al. in U.S. Pat. No. 5,074,856, all three assigned to Kimberly-Clark Corporation.
Compared with earlier plain, flat sanitary napkins, a curved product with elasticized edges generally performs well, offering the advantage, for example, of greater comfort and security. The side edges tend to form a natural curve to better fit the body and a barrier to help prevent side leakage of menstrual fluids. However, in some applications there may be a tendency for the raised side edges to collapse against, or to fold in on top of, the absorbent element thereby allowing the panty elastic to be exposed. Thus, such a side edge no longer functions properly, and there may be leakage and staining of the panty as well as discomfort for the user.
Another form of conventional sanitary napkin, a flat pad with garment attachment panels (wings or flaps), potentially offers some of the same functional improvements and advantages over a plain pad as does the curved product with raised side edges. Typically, the form of this product before use is a flat pad with a pair of opposite garment attachment panels extending laterally outward from an absorbent element. The panels can be formed out of the cover and the baffle. In use, the absorbent element overlays the crotch portion of the panty in the normal way, and the panels are folded under to encircle the crotch portion. The panels may be secured beneath the panty to each other and/or to the panty crotch portion by suitable adhesive or mechanical fasteners. In use, the relative lateral disposition of the point at which each panel is folded (line of fold) is determined substantially by the user in a somewhat random fashion. Between users, or successive applications by a single user, there may be substantial variation in “fit” and working configuration with respect to the spacing of the fold in the panel from the edge of the absorbent and with respect to the disposition of the panty elastic relative to the edge of the absorbent and to the fold. Performance of the sanitary napkin may vary accordingly.
The garment attachment panels on flat conventional pads typically are designed to wrap around or fold over the panty elastic and form an upward element that fits into the groin of the wearer. Typically, the panels are nonabsorbent or minimally absorbent. This arrangement places additional nonabsorbent material in the crotch region, and during use the added material has a tendency to fold over onto the absorbent element. For the comfort and protection of an appropriate fit in the groin, the user is dependent on appropriate disposition and behavior of the panty elastic.
Van Tilburg (U.S. Pat. Nos. 4,589,876 and 4,687,478) and Mattingly (U.S. Pat. No. 4,608,047) disclose variations on and potential improvements over the general form of a flat pad with garment attachment panels referred to above.
The disclosures of the two Van Tilburg patents are substantially similar. They show a flat pad with laterally extending panels which fold over the panty elastic at the edge of the crotch portion but do not encircle the crotch portion. Each panel has two substantially parallel “lines of juncture” which provide “axes of flexibility.” The axes of flexibility determine where each panel folds upward, in relation to the absorbent edge, and downward over the elastic edge of the panty. In use, it is intended that the panty elastic is pulled up into the groin so that the panel, enfolded about it, lies against the respective laterally, outward-facing surface of the labia majora. This forms a dam against lateral fluid flow and prevents side leakage. However, the desired configuration is not easily obtained in practice. Because the panty elastic is allowed to go up into the groin, the panels must be of sufficient length to cover the panty elastic throughout the length of the labia majora. Making the panels long can create a problem in that the end portions of the panels, toward the front and back of the pad, which have been folded around the panty crotch, are “fighting” with the panty elastic which is flaring out and cupping to the body. This can result in discomfort for the user and can cause the panels to come loose from the panty during wear. When the panels come loose, the panty elastic will tend to push the panels up onto the absorbent.
The napkin design taught by Mattingly is essentially that described above, for a conventional flat pad with garment attachment panels, but the disclosure is directed particularly to the “drapability” or sufficient flexibility of the panels. This drapability permits the panels to be folded at any lateral point to match the width of the panty crotch portion and avoid wrinkling. The panels may be of sufficient length to encircle the crotch portion and adhere to each other or to the panty. Mattingly recognizes the problem of the tendency of the panty crotch edge “to enfold onto the body facing surface of the napkin” but suggests allowing the folded panel configuration to be determined by panty crotch width rather than providing positive control of the juxtaposition of the panty elastic with the absorbent element edge.
The disclosures of McCoy (U.S. Pat. No. 4,900,320), Salerno (U.S. Pat. No. 4,940,462) and Seidy (U.S. Pat. No. 5,125,918) depart substantially from conventional flat pads with garment attachment panels described above. In that form, and before use, the panels are essentially lateral extensions of the cover and/or baffle surfaces of the pad. In McCoy, separate panels are affixed beneath the absorbent element, each at a point inward from the longitudinal edge of the absorbent element. This enables the panels to be folded around the crotch portion of the panty, gathering the panty under the absorbent element and removing its edges from proximity with the edges of the absorbent element and the possibility of becoming wet or stained. The attachment of the panels inward of the absorbent risks gathering the panty crotch so much that the user feels some discomfort. The narrower the pad and the wider the panty crotch, the more likely this is to occur. If the absorbent is made wider to avoid this problem, users with narrow crotch widths will experience some discomfort.
In Salerno, the garment attachment panels, which may comprise extensions of the cover or baffle portions of the sanitary napkin, are longitudinally expandable. Such panels, folded over a side of the crotch portion of an undergarment, may more readily conform to the contour of the undergarment and provide lateral protection without bunching of the undergarment. However, Salerno does not suggest use of the garment attachment panels to control lateral disposition of the undergarment crotch portion edge and, particularly, not of an elasticized edge in relation to an absorbent element in such a way as to prevent the elasticized edge from pulling in on top of the absorbent. Salerno's design does not particularly limit the disposition of the garment attachment panels when secured. They do not overlap and fasten together to establish a predetermined configuration when in use.
In Seidy, the garment attachment panels are truncated and supported at the opposite lateral edges of the absorbent element, extending inwardly and somewhat stiffly in a prefolded, flexible position. This enables the panty crotch portion to be maneuvered into position under the absorbent element and retained by the panels without the need for additional attachment adhesive.
As with Mattingly, the McCoy, Salerno and Seidy patents are concerned primarily with various aspects of treatment of the panty crotch portion in relation to the sanitary napkin. Mattingly teaches the avoidance of wrinkling, McCoy teaches a particular approach to shielding the crotch portion from wetting and staining, Salerno teaches side protection along the entire longitudinal edges of the napkin without bunching of the undergarment, and Seidy teaches the provision of panty edge shielding flaps without requiring additional attachment adhesive. None of these references suggest making use of garment attachment panels to enhance directly the performance of a sanitary napkin as a whole.